AWS credentials provider chain that looks for credentials in this order:

Environment Variables -
AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY
(RECOMMENDED since they are recognized by all the AWS SDKs and CLI except for .NET),
or AWS_ACCESS_KEY and AWS_SECRET_KEY (only recognized by Java SDK)

Java System Properties - aws.accessKeyId and aws.secretKey

Credential profiles file at the default location (~/.aws/credentials) shared by all AWS SDKs and the AWS CLI

Credentials delivered through the Amazon EC2 container service if AWS_CONTAINER_CREDENTIALS_RELATIVE_URI" environment variable is set
and security manager has permission to access the variable,

Instance profile credentials delivered through the Amazon EC2 metadata service